Experimental evidences of substitutional solution of Er dopant in Er-doped SnO2 nanoparticles

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology Vol. 15; no. 1; p. 1
• Main Authors: Aragón, F. H., Coaquira, J. A. H., Hidalgo, P., Cohen, R., Nagamine, L. C. C. M., da Silva, S. W., Morais, P. C., Brito, H. F.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 2013; Springer; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Inorganic Chemistry; Lasers; Materials Science; Methods of nanofabrication; Nanocrystalline materials; Nanoparticles; Nanoscale materials and structures: fabrication and characterization; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Nanotechnology; Optical Devices; Optics; Photonics; Physical Chemistry; Physics; Research Paper; Specific phase transitions; Structural transitions in nanoscale materials; Structure of solids and liquids; crystallography; Nanoparticles; Rare-earth doped semiconducting tin oxide; TEM images; XRD diffraction; Mössbauer spectroscopy; Doping; Conduction electron; Moessbauer spectroscopy; XRD; Isomers; Precursor; Electric field gradients; Crystallites; Stress effects; Polymers; Nanomaterial synthesis; Crystal structure; Electronic properties; Vacancies; Tetragonal lattices; Phase transformations; Bond angle; Lattice parameters; Tin additions; Transmission electron microscopy; Crystal-phase transformations; Nanostructured materials
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-012-1343-1

Structural and hyperfine properties of Er-doped SnO 2 nanoparticles synthesized by a polymer precursor method are reported in this study. X-ray diffraction patterns of samples doped with erbium up to 10 mol % indicate the formation of the tetragonal rutile phase. The mean crystallite size shows a rapid decrease from ~12 nm for the undoped sample down to ~4 nm for the 10 mol % Er-doped sample. Structural changes as a function of the Er content, i.e., changes in the lattice constants, Sn–O bond distances and bond angles, strongly suggest the substitutional solution of Er 3+ ions and the onset of oxygen vacancies throughout the SnO 2 lattice. No dipolar-magnetic interaction is determined from the Mössbauer spectra which are well resolved by fitting with a distribution of electric-quadrupole doublets. Changes observed in the quadrupole splitting as a function of the Er content have been associated to the local strain induced by the cationic size mismatch and oxygen vacancies. This local strain affects the lattice contribution of the electric field gradient. The linear increase of the isomer shift is assigned to the enhancement of the oxygen vacancies as the Er content is increased. It is found that the oxygen vacancies provide with conduction electrons to the Er-doped SnO 2 nanoparticulated system, therefore modifying its electronic properties.